3. Keep it off other cards. Request that your driver's license number or any other identification number is not the same as your Social Security number.

4. Never give out your SSN, credit card number, or other personal information over the phone unless you have a trusted business relationship with the organization and initiated the call using a verified phone number.

5. Avoid including your SSN on medical history forms and job applications.

7. Keep it away from accounts. If your financial institution attempts to use your SSN as an account number, ask them to change it immediately.

8. If a government agency requests your SSN, look for a Privacy Act notice. This will state whether a SSN is required, how it will be used, how it is protected, and what happens if you don’t provide it.

9. Check your Social Security Earnings Statement each year for signs of fraud. You should receive it yearly approximately three months before your birthday.

10. Don’t use the last four numbers. Many businesses have started using the last four digits of your SSN for remote identification purposes for access to online banking and telephone banking via both Interactive Voice Response (IVR) and live telephone agent. It may be used in combination with other simple and widely available identifiers like a ZIP code. A number of institutions have used it as a default password when you reset your telephone, online or even ATM PIN. It is not a recommended practice.

Top 5 Worst Places to Use Your SSN

McAfee, the anti-virus company, recently made headlines when it released a study of the most dangerous places to use your Social Security number. The places were ranked based on the number of data breaches—where hackers break into computer systems and steal personal information—from January 2009 through October 2010. The results are disturbing:

What is most maddening is that these are exactly the kinds of institutions where you have no alternative but to give up your Social Security number to gain services. So what do you do when, say, standing in line at university registration or on the phone with a financial institution and you’re asked to cough it up?

1. Ask questions. First, ask if they really need your Social Security number. Are there other options? Name and address, or date of birth perhaps? Many types of businesses cannot, by law, require you to give up your SSN, so you might just have a call center employee seeking the shortest route to a finished call.

2. Never give your SSN or other information to anyone from anywhere who calls you. This could be a well-known scam where criminals pose as reputable institutions. If your bank does call you, ask them for a call-back number and verify that it’s legit online.

3. Visit annualcreditreport.com to get a free copy of your credit reports from Equifax, Experian and TransUnion, and make sure nothing is amiss. Then consider a fraud and credit monitoring service or a similar plan that will notify you of any unusual activity.